3 * Bluetooth HCI UART driver
5 * Copyright (C) 2002-2003 Fabrizio Gennari <fabrizio.gennari@philips.com>
6 * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 #include <linux/module.h>
27 #include <linux/kernel.h>
28 #include <linux/init.h>
29 #include <linux/types.h>
30 #include <linux/fcntl.h>
31 #include <linux/interrupt.h>
32 #include <linux/ptrace.h>
33 #include <linux/poll.h>
35 #include <linux/slab.h>
36 #include <linux/tty.h>
37 #include <linux/errno.h>
38 #include <linux/string.h>
39 #include <linux/signal.h>
40 #include <linux/ioctl.h>
41 #include <linux/skbuff.h>
42 #include <linux/bitrev.h>
43 #include <asm/unaligned.h>
45 #include <net/bluetooth/bluetooth.h>
46 #include <net/bluetooth/hci_core.h>
52 static bool txcrc
= 1;
53 static bool hciextn
= 1;
55 #define BCSP_TXWINSIZE 4
57 #define BCSP_ACK_PKT 0x05
58 #define BCSP_LE_PKT 0x06
61 struct sk_buff_head unack
; /* Unack'ed packets queue */
62 struct sk_buff_head rel
; /* Reliable packets queue */
63 struct sk_buff_head unrel
; /* Unreliable packets queue */
65 unsigned long rx_count
;
66 struct sk_buff
*rx_skb
;
67 u8 rxseq_txack
; /* rxseq == txack. */
68 u8 rxack
; /* Last packet sent by us that the peer ack'ed */
69 struct timer_list tbcsp
;
72 BCSP_W4_PKT_DELIMITER
,
86 u8 txack_req
; /* Do we need to send ack's to the peer? */
88 /* Reliable packet sequence number - used to assign seq to each rel pkt. */
92 /* ---- BCSP CRC calculation ---- */
94 /* Table for calculating CRC for polynomial 0x1021, LSB processed first,
95 initial value 0xffff, bits shifted in reverse order. */
97 static const u16 crc_table
[] = {
98 0x0000, 0x1081, 0x2102, 0x3183,
99 0x4204, 0x5285, 0x6306, 0x7387,
100 0x8408, 0x9489, 0xa50a, 0xb58b,
101 0xc60c, 0xd68d, 0xe70e, 0xf78f
104 /* Initialise the crc calculator */
105 #define BCSP_CRC_INIT(x) x = 0xffff
108 Update crc with next data byte
111 The data byte is treated as two nibbles. The crc is generated
112 in reverse, i.e., bits are fed into the register from the top.
114 static void bcsp_crc_update(u16
*crc
, u8 d
)
118 reg
= (reg
>> 4) ^ crc_table
[(reg
^ d
) & 0x000f];
119 reg
= (reg
>> 4) ^ crc_table
[(reg
^ (d
>> 4)) & 0x000f];
124 /* ---- BCSP core ---- */
126 static void bcsp_slip_msgdelim(struct sk_buff
*skb
)
128 const char pkt_delim
= 0xc0;
130 memcpy(skb_put(skb
, 1), &pkt_delim
, 1);
133 static void bcsp_slip_one_byte(struct sk_buff
*skb
, u8 c
)
135 const char esc_c0
[2] = { 0xdb, 0xdc };
136 const char esc_db
[2] = { 0xdb, 0xdd };
140 memcpy(skb_put(skb
, 2), &esc_c0
, 2);
143 memcpy(skb_put(skb
, 2), &esc_db
, 2);
146 memcpy(skb_put(skb
, 1), &c
, 1);
150 static int bcsp_enqueue(struct hci_uart
*hu
, struct sk_buff
*skb
)
152 struct bcsp_struct
*bcsp
= hu
->priv
;
154 if (skb
->len
> 0xFFF) {
155 BT_ERR("Packet too long");
160 switch (bt_cb(skb
)->pkt_type
) {
161 case HCI_ACLDATA_PKT
:
162 case HCI_COMMAND_PKT
:
163 skb_queue_tail(&bcsp
->rel
, skb
);
166 case HCI_SCODATA_PKT
:
167 skb_queue_tail(&bcsp
->unrel
, skb
);
171 BT_ERR("Unknown packet type");
179 static struct sk_buff
*bcsp_prepare_pkt(struct bcsp_struct
*bcsp
, u8
*data
,
180 int len
, int pkt_type
)
182 struct sk_buff
*nskb
;
184 u16
BCSP_CRC_INIT(bcsp_txmsg_crc
);
188 case HCI_ACLDATA_PKT
:
189 chan
= 6; /* BCSP ACL channel */
190 rel
= 1; /* reliable channel */
192 case HCI_COMMAND_PKT
:
193 chan
= 5; /* BCSP cmd/evt channel */
194 rel
= 1; /* reliable channel */
196 case HCI_SCODATA_PKT
:
197 chan
= 7; /* BCSP SCO channel */
198 rel
= 0; /* unreliable channel */
201 chan
= 1; /* BCSP LE channel */
202 rel
= 0; /* unreliable channel */
205 chan
= 0; /* BCSP internal channel */
206 rel
= 0; /* unreliable channel */
209 BT_ERR("Unknown packet type");
213 if (hciextn
&& chan
== 5) {
214 __le16 opcode
= ((struct hci_command_hdr
*)data
)->opcode
;
216 /* Vendor specific commands */
217 if (hci_opcode_ogf(__le16_to_cpu(opcode
)) == 0x3f) {
218 u8 desc
= *(data
+ HCI_COMMAND_HDR_SIZE
);
219 if ((desc
& 0xf0) == 0xc0) {
220 data
+= HCI_COMMAND_HDR_SIZE
+ 1;
221 len
-= HCI_COMMAND_HDR_SIZE
+ 1;
227 /* Max len of packet: (original len +4(bcsp hdr) +2(crc))*2
228 (because bytes 0xc0 and 0xdb are escaped, worst case is
229 when the packet is all made of 0xc0 and 0xdb :) )
230 + 2 (0xc0 delimiters at start and end). */
232 nskb
= alloc_skb((len
+ 6) * 2 + 2, GFP_ATOMIC
);
236 bt_cb(nskb
)->pkt_type
= pkt_type
;
238 bcsp_slip_msgdelim(nskb
);
240 hdr
[0] = bcsp
->rxseq_txack
<< 3;
242 BT_DBG("We request packet no %u to card", bcsp
->rxseq_txack
);
245 hdr
[0] |= 0x80 + bcsp
->msgq_txseq
;
246 BT_DBG("Sending packet with seqno %u", bcsp
->msgq_txseq
);
247 bcsp
->msgq_txseq
= (bcsp
->msgq_txseq
+ 1) & 0x07;
253 hdr
[1] = ((len
<< 4) & 0xff) | chan
;
255 hdr
[3] = ~(hdr
[0] + hdr
[1] + hdr
[2]);
257 /* Put BCSP header */
258 for (i
= 0; i
< 4; i
++) {
259 bcsp_slip_one_byte(nskb
, hdr
[i
]);
262 bcsp_crc_update(&bcsp_txmsg_crc
, hdr
[i
]);
266 for (i
= 0; i
< len
; i
++) {
267 bcsp_slip_one_byte(nskb
, data
[i
]);
270 bcsp_crc_update(&bcsp_txmsg_crc
, data
[i
]);
275 bcsp_txmsg_crc
= bitrev16(bcsp_txmsg_crc
);
276 bcsp_slip_one_byte(nskb
, (u8
) ((bcsp_txmsg_crc
>> 8) & 0x00ff));
277 bcsp_slip_one_byte(nskb
, (u8
) (bcsp_txmsg_crc
& 0x00ff));
280 bcsp_slip_msgdelim(nskb
);
284 /* This is a rewrite of pkt_avail in ABCSP */
285 static struct sk_buff
*bcsp_dequeue(struct hci_uart
*hu
)
287 struct bcsp_struct
*bcsp
= hu
->priv
;
291 /* First of all, check for unreliable messages in the queue,
292 since they have priority */
294 if ((skb
= skb_dequeue(&bcsp
->unrel
)) != NULL
) {
295 struct sk_buff
*nskb
= bcsp_prepare_pkt(bcsp
, skb
->data
, skb
->len
, bt_cb(skb
)->pkt_type
);
300 skb_queue_head(&bcsp
->unrel
, skb
);
301 BT_ERR("Could not dequeue pkt because alloc_skb failed");
305 /* Now, try to send a reliable pkt. We can only send a
306 reliable packet if the number of packets sent but not yet ack'ed
307 is < than the winsize */
309 spin_lock_irqsave_nested(&bcsp
->unack
.lock
, flags
, SINGLE_DEPTH_NESTING
);
311 if (bcsp
->unack
.qlen
< BCSP_TXWINSIZE
&& (skb
= skb_dequeue(&bcsp
->rel
)) != NULL
) {
312 struct sk_buff
*nskb
= bcsp_prepare_pkt(bcsp
, skb
->data
, skb
->len
, bt_cb(skb
)->pkt_type
);
314 __skb_queue_tail(&bcsp
->unack
, skb
);
315 mod_timer(&bcsp
->tbcsp
, jiffies
+ HZ
/ 4);
316 spin_unlock_irqrestore(&bcsp
->unack
.lock
, flags
);
319 skb_queue_head(&bcsp
->rel
, skb
);
320 BT_ERR("Could not dequeue pkt because alloc_skb failed");
324 spin_unlock_irqrestore(&bcsp
->unack
.lock
, flags
);
326 /* We could not send a reliable packet, either because there are
327 none or because there are too many unack'ed pkts. Did we receive
328 any packets we have not acknowledged yet ? */
330 if (bcsp
->txack_req
) {
331 /* if so, craft an empty ACK pkt and send it on BCSP unreliable
333 struct sk_buff
*nskb
= bcsp_prepare_pkt(bcsp
, NULL
, 0, BCSP_ACK_PKT
);
337 /* We have nothing to send */
341 static int bcsp_flush(struct hci_uart
*hu
)
347 /* Remove ack'ed packets */
348 static void bcsp_pkt_cull(struct bcsp_struct
*bcsp
)
350 struct sk_buff
*skb
, *tmp
;
352 int i
, pkts_to_be_removed
;
355 spin_lock_irqsave(&bcsp
->unack
.lock
, flags
);
357 pkts_to_be_removed
= skb_queue_len(&bcsp
->unack
);
358 seqno
= bcsp
->msgq_txseq
;
360 while (pkts_to_be_removed
) {
361 if (bcsp
->rxack
== seqno
)
363 pkts_to_be_removed
--;
364 seqno
= (seqno
- 1) & 0x07;
367 if (bcsp
->rxack
!= seqno
)
368 BT_ERR("Peer acked invalid packet");
370 BT_DBG("Removing %u pkts out of %u, up to seqno %u",
371 pkts_to_be_removed
, skb_queue_len(&bcsp
->unack
),
375 skb_queue_walk_safe(&bcsp
->unack
, skb
, tmp
) {
376 if (i
>= pkts_to_be_removed
)
380 __skb_unlink(skb
, &bcsp
->unack
);
384 if (skb_queue_empty(&bcsp
->unack
))
385 del_timer(&bcsp
->tbcsp
);
387 spin_unlock_irqrestore(&bcsp
->unack
.lock
, flags
);
389 if (i
!= pkts_to_be_removed
)
390 BT_ERR("Removed only %u out of %u pkts", i
, pkts_to_be_removed
);
393 /* Handle BCSP link-establishment packets. When we
394 detect a "sync" packet, symptom that the BT module has reset,
395 we do nothing :) (yet) */
396 static void bcsp_handle_le_pkt(struct hci_uart
*hu
)
398 struct bcsp_struct
*bcsp
= hu
->priv
;
399 u8 conf_pkt
[4] = { 0xad, 0xef, 0xac, 0xed };
400 u8 conf_rsp_pkt
[4] = { 0xde, 0xad, 0xd0, 0xd0 };
401 u8 sync_pkt
[4] = { 0xda, 0xdc, 0xed, 0xed };
403 /* spot "conf" pkts and reply with a "conf rsp" pkt */
404 if (bcsp
->rx_skb
->data
[1] >> 4 == 4 && bcsp
->rx_skb
->data
[2] == 0 &&
405 !memcmp(&bcsp
->rx_skb
->data
[4], conf_pkt
, 4)) {
406 struct sk_buff
*nskb
= alloc_skb(4, GFP_ATOMIC
);
408 BT_DBG("Found a LE conf pkt");
411 memcpy(skb_put(nskb
, 4), conf_rsp_pkt
, 4);
412 bt_cb(nskb
)->pkt_type
= BCSP_LE_PKT
;
414 skb_queue_head(&bcsp
->unrel
, nskb
);
415 hci_uart_tx_wakeup(hu
);
417 /* Spot "sync" pkts. If we find one...disaster! */
418 else if (bcsp
->rx_skb
->data
[1] >> 4 == 4 && bcsp
->rx_skb
->data
[2] == 0 &&
419 !memcmp(&bcsp
->rx_skb
->data
[4], sync_pkt
, 4)) {
420 BT_ERR("Found a LE sync pkt, card has reset");
424 static inline void bcsp_unslip_one_byte(struct bcsp_struct
*bcsp
, unsigned char byte
)
426 const u8 c0
= 0xc0, db
= 0xdb;
428 switch (bcsp
->rx_esc_state
) {
429 case BCSP_ESCSTATE_NOESC
:
432 bcsp
->rx_esc_state
= BCSP_ESCSTATE_ESC
;
435 memcpy(skb_put(bcsp
->rx_skb
, 1), &byte
, 1);
436 if ((bcsp
->rx_skb
-> data
[0] & 0x40) != 0 &&
437 bcsp
->rx_state
!= BCSP_W4_CRC
)
438 bcsp_crc_update(&bcsp
->message_crc
, byte
);
443 case BCSP_ESCSTATE_ESC
:
446 memcpy(skb_put(bcsp
->rx_skb
, 1), &c0
, 1);
447 if ((bcsp
->rx_skb
-> data
[0] & 0x40) != 0 &&
448 bcsp
->rx_state
!= BCSP_W4_CRC
)
449 bcsp_crc_update(&bcsp
-> message_crc
, 0xc0);
450 bcsp
->rx_esc_state
= BCSP_ESCSTATE_NOESC
;
455 memcpy(skb_put(bcsp
->rx_skb
, 1), &db
, 1);
456 if ((bcsp
->rx_skb
-> data
[0] & 0x40) != 0 &&
457 bcsp
->rx_state
!= BCSP_W4_CRC
)
458 bcsp_crc_update(&bcsp
-> message_crc
, 0xdb);
459 bcsp
->rx_esc_state
= BCSP_ESCSTATE_NOESC
;
464 BT_ERR ("Invalid byte %02x after esc byte", byte
);
465 kfree_skb(bcsp
->rx_skb
);
467 bcsp
->rx_state
= BCSP_W4_PKT_DELIMITER
;
473 static void bcsp_complete_rx_pkt(struct hci_uart
*hu
)
475 struct bcsp_struct
*bcsp
= hu
->priv
;
478 if (bcsp
->rx_skb
->data
[0] & 0x80) { /* reliable pkt */
479 BT_DBG("Received seqno %u from card", bcsp
->rxseq_txack
);
481 bcsp
->rxseq_txack
%= 0x8;
484 /* If needed, transmit an ack pkt */
485 hci_uart_tx_wakeup(hu
);
488 bcsp
->rxack
= (bcsp
->rx_skb
->data
[0] >> 3) & 0x07;
489 BT_DBG("Request for pkt %u from card", bcsp
->rxack
);
492 if ((bcsp
->rx_skb
->data
[1] & 0x0f) == 6 &&
493 bcsp
->rx_skb
->data
[0] & 0x80) {
494 bt_cb(bcsp
->rx_skb
)->pkt_type
= HCI_ACLDATA_PKT
;
496 } else if ((bcsp
->rx_skb
->data
[1] & 0x0f) == 5 &&
497 bcsp
->rx_skb
->data
[0] & 0x80) {
498 bt_cb(bcsp
->rx_skb
)->pkt_type
= HCI_EVENT_PKT
;
500 } else if ((bcsp
->rx_skb
->data
[1] & 0x0f) == 7) {
501 bt_cb(bcsp
->rx_skb
)->pkt_type
= HCI_SCODATA_PKT
;
503 } else if ((bcsp
->rx_skb
->data
[1] & 0x0f) == 1 &&
504 !(bcsp
->rx_skb
->data
[0] & 0x80)) {
505 bcsp_handle_le_pkt(hu
);
511 struct hci_event_hdr hdr
;
512 u8 desc
= (bcsp
->rx_skb
->data
[1] & 0x0f);
514 if (desc
!= 0 && desc
!= 1) {
517 skb_pull(bcsp
->rx_skb
, 4);
518 memcpy(skb_push(bcsp
->rx_skb
, 1), &desc
, 1);
521 hdr
.plen
= bcsp
->rx_skb
->len
;
522 memcpy(skb_push(bcsp
->rx_skb
, HCI_EVENT_HDR_SIZE
), &hdr
, HCI_EVENT_HDR_SIZE
);
523 bt_cb(bcsp
->rx_skb
)->pkt_type
= HCI_EVENT_PKT
;
525 hci_recv_frame(hu
->hdev
, bcsp
->rx_skb
);
527 BT_ERR ("Packet for unknown channel (%u %s)",
528 bcsp
->rx_skb
->data
[1] & 0x0f,
529 bcsp
->rx_skb
->data
[0] & 0x80 ?
530 "reliable" : "unreliable");
531 kfree_skb(bcsp
->rx_skb
);
534 kfree_skb(bcsp
->rx_skb
);
536 /* Pull out BCSP hdr */
537 skb_pull(bcsp
->rx_skb
, 4);
539 hci_recv_frame(hu
->hdev
, bcsp
->rx_skb
);
542 bcsp
->rx_state
= BCSP_W4_PKT_DELIMITER
;
546 static u16
bscp_get_crc(struct bcsp_struct
*bcsp
)
548 return get_unaligned_be16(&bcsp
->rx_skb
->data
[bcsp
->rx_skb
->len
- 2]);
552 static int bcsp_recv(struct hci_uart
*hu
, void *data
, int count
)
554 struct bcsp_struct
*bcsp
= hu
->priv
;
557 BT_DBG("hu %p count %d rx_state %d rx_count %ld",
558 hu
, count
, bcsp
->rx_state
, bcsp
->rx_count
);
562 if (bcsp
->rx_count
) {
564 BT_ERR("Short BCSP packet");
565 kfree_skb(bcsp
->rx_skb
);
566 bcsp
->rx_state
= BCSP_W4_PKT_START
;
569 bcsp_unslip_one_byte(bcsp
, *ptr
);
575 switch (bcsp
->rx_state
) {
576 case BCSP_W4_BCSP_HDR
:
577 if ((0xff & (u8
) ~ (bcsp
->rx_skb
->data
[0] + bcsp
->rx_skb
->data
[1] +
578 bcsp
->rx_skb
->data
[2])) != bcsp
->rx_skb
->data
[3]) {
579 BT_ERR("Error in BCSP hdr checksum");
580 kfree_skb(bcsp
->rx_skb
);
581 bcsp
->rx_state
= BCSP_W4_PKT_DELIMITER
;
585 if (bcsp
->rx_skb
->data
[0] & 0x80 /* reliable pkt */
586 && (bcsp
->rx_skb
->data
[0] & 0x07) != bcsp
->rxseq_txack
) {
587 BT_ERR ("Out-of-order packet arrived, got %u expected %u",
588 bcsp
->rx_skb
->data
[0] & 0x07, bcsp
->rxseq_txack
);
590 kfree_skb(bcsp
->rx_skb
);
591 bcsp
->rx_state
= BCSP_W4_PKT_DELIMITER
;
595 bcsp
->rx_state
= BCSP_W4_DATA
;
596 bcsp
->rx_count
= (bcsp
->rx_skb
->data
[1] >> 4) +
597 (bcsp
->rx_skb
->data
[2] << 4); /* May be 0 */
601 if (bcsp
->rx_skb
->data
[0] & 0x40) { /* pkt with crc */
602 bcsp
->rx_state
= BCSP_W4_CRC
;
605 bcsp_complete_rx_pkt(hu
);
609 if (bitrev16(bcsp
->message_crc
) != bscp_get_crc(bcsp
)) {
610 BT_ERR ("Checksum failed: computed %04x received %04x",
611 bitrev16(bcsp
->message_crc
),
614 kfree_skb(bcsp
->rx_skb
);
615 bcsp
->rx_state
= BCSP_W4_PKT_DELIMITER
;
619 skb_trim(bcsp
->rx_skb
, bcsp
->rx_skb
->len
- 2);
620 bcsp_complete_rx_pkt(hu
);
623 case BCSP_W4_PKT_DELIMITER
:
626 bcsp
->rx_state
= BCSP_W4_PKT_START
;
629 /*BT_ERR("Ignoring byte %02x", *ptr);*/
635 case BCSP_W4_PKT_START
:
642 bcsp
->rx_state
= BCSP_W4_BCSP_HDR
;
644 bcsp
->rx_esc_state
= BCSP_ESCSTATE_NOESC
;
645 BCSP_CRC_INIT(bcsp
->message_crc
);
647 /* Do not increment ptr or decrement count
648 * Allocate packet. Max len of a BCSP pkt=
649 * 0xFFF (payload) +4 (header) +2 (crc) */
651 bcsp
->rx_skb
= bt_skb_alloc(0x1005, GFP_ATOMIC
);
653 BT_ERR("Can't allocate mem for new packet");
654 bcsp
->rx_state
= BCSP_W4_PKT_DELIMITER
;
666 /* Arrange to retransmit all messages in the relq. */
667 static void bcsp_timed_event(unsigned long arg
)
669 struct hci_uart
*hu
= (struct hci_uart
*) arg
;
670 struct bcsp_struct
*bcsp
= hu
->priv
;
674 BT_DBG("hu %p retransmitting %u pkts", hu
, bcsp
->unack
.qlen
);
676 spin_lock_irqsave_nested(&bcsp
->unack
.lock
, flags
, SINGLE_DEPTH_NESTING
);
678 while ((skb
= __skb_dequeue_tail(&bcsp
->unack
)) != NULL
) {
679 bcsp
->msgq_txseq
= (bcsp
->msgq_txseq
- 1) & 0x07;
680 skb_queue_head(&bcsp
->rel
, skb
);
683 spin_unlock_irqrestore(&bcsp
->unack
.lock
, flags
);
685 hci_uart_tx_wakeup(hu
);
688 static int bcsp_open(struct hci_uart
*hu
)
690 struct bcsp_struct
*bcsp
;
694 bcsp
= kzalloc(sizeof(*bcsp
), GFP_KERNEL
);
699 skb_queue_head_init(&bcsp
->unack
);
700 skb_queue_head_init(&bcsp
->rel
);
701 skb_queue_head_init(&bcsp
->unrel
);
703 init_timer(&bcsp
->tbcsp
);
704 bcsp
->tbcsp
.function
= bcsp_timed_event
;
705 bcsp
->tbcsp
.data
= (u_long
) hu
;
707 bcsp
->rx_state
= BCSP_W4_PKT_DELIMITER
;
715 static int bcsp_close(struct hci_uart
*hu
)
717 struct bcsp_struct
*bcsp
= hu
->priv
;
722 skb_queue_purge(&bcsp
->unack
);
723 skb_queue_purge(&bcsp
->rel
);
724 skb_queue_purge(&bcsp
->unrel
);
725 del_timer(&bcsp
->tbcsp
);
731 static struct hci_uart_proto bcsp
= {
735 .enqueue
= bcsp_enqueue
,
736 .dequeue
= bcsp_dequeue
,
741 int __init
bcsp_init(void)
743 int err
= hci_uart_register_proto(&bcsp
);
746 BT_INFO("HCI BCSP protocol initialized");
748 BT_ERR("HCI BCSP protocol registration failed");
753 int __exit
bcsp_deinit(void)
755 return hci_uart_unregister_proto(&bcsp
);
758 module_param(txcrc
, bool, 0644);
759 MODULE_PARM_DESC(txcrc
, "Transmit CRC with every BCSP packet");
761 module_param(hciextn
, bool, 0644);
762 MODULE_PARM_DESC(hciextn
, "Convert HCI Extensions into BCSP packets");